The Adventures of Kit Carson (1951–1960)

As a child in the early 1950s I regularly watched "The Adventures of Kit Carson". However I'm puzzled by a particular omission from the list of characters. I remember that in many episodes Kit Carson had as his sidekick a little girl called Joan. However, there's no mention of Joan in the cast list. Please can anyone explain or help with this? (The reason I remember 'Joan' so clearly is because when I played cowboys-and-Indians with my many boy cousins they always insisted that I be Joan! In addition I have just made contact with someone else who remembers watching "The Adventures of Kit Carson" and he confirmed that Joan was a regular participant, commenting that the relationship would never be allowed today!